There's always the difference between "'it's working' and 'it's working well' with system".
That being said, I've managed to stream HO-D off of a 7200rpm with a USB 2.0 connection.

Your CPU is fine. Remember to load multiple instances instead of everything on one.
Cubase will then be able to evenly divide the instances onto the two cores. If you
don't do that, one core will then be easily overloaded and let's just say there
are cheaper ways to heat your room.

RAM is also good with 16GB. Depending on what you're loading, it can be a bit of a stretch.
You need to subtract a 1-2GB for the OS and depending on the patch, it can easily
hit 1GB. Remember that the mainstay of the higher tiered libraries (Diamond
and Platinum) is the multiple mic-positions, which are available.

Try to stay away from the heavy Master patches and use the lite ones. What you
can do, is create a track with a lite patch, then load the Master and export to .wav.
You won't be able to edit anymore, but it'll free up your resources.
Also possible is changing the "Sample Cache" settings (p. 58 and / or purging the
samples (p. 60). Check out the manual for more details (link).

Currently, the main problem lies with your OS harddrive, which is rather slow
with its 5400rpm. It'll especially be noticeable with Cubase open. Not sure if
you've ever done a speed check on opening and loading Cubase and VSTis.

I'm actually kind of curious, it sounds like you have a couple of libraries (please
remember that this is an EastWest specific forum, so try mentioning the others
less often).
Have you been experiencing pops and clicks with those when using with your current OS?

As Bryan wrote, consider the regular ComposerCloud (link). You can get an
additional discount on the first month, if you subscribe via the red "Start your
30 days now" button at the top of the window. The CC can be unsubscribed
during any month, whereas the CC X (+1 mic) and the CC Plus (Diamond /
Platinum) are yearly commitments.
You'd be able to check how HO Gold is holding up with your current system.

And when you have the new system, you can get HO Diamond additionally (or upgrade).
Make sure to be subscribed to our newsletter (link), since all sales are presented there.

hermaphroditic "glob" of sound - Ok, I just love that explanation.

Edit: The edit function is time limited to an hour, I think. If anybody ever wants
or needs a comment edited after that, please message me, and I'll be happy to oblige.